Rock drill



Oct. 13, 1942. C, QSGOD 2,298,503

ROCK DRILL Filed March 14, 1941 37 l0'. MUM-aq. agay Patented Get. 13, 1942 JNETELD STAT gara ROCK DRlLL Charles F. Osgood, Claremont, N. H., assigner to Sullivan Machinery Company, a corporation of Massachusetts 17 Claims.

This invention relates to rock drills, and more particularly to an improved rotation mechanism for the drill steel of a hammer rock drill whereby drill steel rotation may be interrupted at will Without interrupting operation of the hammer motor.

An object of the present invention is to provide an improved drill steel rotation mechanism for a hammer rock drill. Another object is to provide an improved drill steel rotation mechanism having embodied therein improved means for interrupting drill steel rotation at the oper- Aators will. A further object is to provide a drill steel rotation mechanism embodying an intermittent grip mechanism and releasable clutch means associated with an element of said intermittent grip mechanism for controlling drill steel rotation. Yet another object is to provide an improved-drill steel rotation .mechanism embodying an intermittent grip mechanism including a carrier element for the gripping means and releasable clutch means associated with the carrier element for controlling the functioning thereof whereby steel rotation may be controlled at will. A still further object is to provide an improved uid actuated clutch means for controlling drill steel rotation and controlled by the throttle valve ofthe drill hammer motor. A still further object Ais to provide an improved drill steel rotation mechanism embodying relatively rotatable ratchet and pawl carrier elements and clutch means for releasing the pawl carrier element for free rotation to interrupt steel rotation, and for holding Athe pawl carrier element against rotation at will when rotation of the drill steel is desired. An-

other object is to provide an improved drill steel rotation mechanism embodying a rotatable pawl carrier and an associated rifle bar and improved clutch means for disconnecting the pawl carrier -from the rifle bar when it is desired to interrupt drill steel rotation. Other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawing there are shown for illustrative purposes two forms which the invention may assume in practice.

In this drawing:

Fig. 1 is a View in longitudinal vertical section through a drill hammer motor of a rock drill with which the improved steel rotation mechanism is associated.

Fig. 2 is a fragmentary sectional view taken on the plane of Fig. 1, showing parts in a different position.

Fig. 3 is a perspective view of the control clutch.

Fig. 4 is a cross sectional View taken on line 4-4 of Fig. 1.

Fig. 5 is a cross sectional view taken on line 5 5 of Fig. 1.

Fig. 6 is a detail sectional view similar to Fig. 2 but taken on a different plane through the throttle valve, showing parts in a position to effect drill steel rotation.

Fig. 7 is a View similar to Fig. 6 showing the parts in a position to effect interruption of steel rotation.

Fig. 8 is a cross sectional view taken on line 8-8 of Fig. 2.

Fig. 9 is a view similar to Fig. 2 showing a modied form of the invention.

In both illustrative embodiments of the invention the improved drill steel rotation mechanism is embodied in a hammer rock drill and is associated with a drill hammer motor of the pressure iiuid actuated, reciprocating hammer piston type. The drill hammer motor comprises a motor cylinder I having a bore 2 containing a reciprocatory hammer piston 3. The hammer piston has a striking bar A for delivering impact blows to the shank of a conventional drill steel (not shown) carried within the usual rock drill chuck in the manner well known to those skilled in the art. The hammer motor cylinder has a rear head block 5 carrying a throttle valve 6 for controlling the flow of pressure iiuid from a suitable source of supply through a passage] to a fluid distributing valve mechanism 8. This valve mechanism includes fluid actuated, uid distributing valves which control the distribution of motive uid with respect to the motor cylinder to effect reciprocation of the hammer piston in a well known manner.

As is usual in rock drills of the type disclosed, a rotation mechanism operated by the hammer piston is provided for rotating the drill steel as the latter is percussively actuated. This rotation mechanism includes a spirally grooved rifle bar S slidingly interlocked with a riiie nut l0 secured within the hammer piston. Associated with the rifle bar is an intermittent grip mechanism for vention shown in Figs. 1 to 8, inclusive, it will be observed that a rotatable ratchet ring I2 is secured to the rifle bar 9 and has internal ratchet teeth I3. Arranged concentrically within the ratchet ring is a pawl carrier I4 which carries usual spring pressed pawls I5 engaging the teeth of the ratchet ring. 'I'his pawl carrier is rotatably mounted on a bearing sleeve supported by a stub shaft I6 secured to the rear head block 5 and projecting axially within the pawl carrier and ratchet ring in the manner shown. The rifle bar has a rearward cylindric projection I1 journaled within a bore within the stub shaft I6. The rear head block has a bore I8 containing a reciprocable piston or plunger I9 formed integral with a jaw clutch member 20. This clutch member has a rearward sleeve portion 2| guided in a bore 22 formed in the rear head block in coaxial relation with the piston containing bore I8, and formed internally of this sleeve portion are splines 23 slidingly interlocked with straight longitudinal splineways 24 on the stub shaft IB. interposed between the clutch member and a bearing element engaging the pawl carrier is a coil spring 25 for urging the clutch member towardV its rearmost released position. The clutch member has clutch teeth 26 engageable with clutch teeth 21 formed on the rear face of the pawl carrier. The throttle valve 6 .has a port 28 for delivering pressure uid to a passage 29 connected to the bore I8 at the rear side ofthe piston I9, to effect movement of the clutchI member into its foremost clutched position. The throttle valve has a groove 30 for connecting the bore I8 at the rear side of `the pistonY I9 to a vent port 3|, for connecting the clutch member to exhaust. When the bore I8 at the rear side of the piston I9 is vented to atmosphere the coiled spring 25 forces the clutch member rearwardlyr into its rearmost released position. The throttle valve has an elongated port 32 forY connecting the motor supply passage 1 to the source of fluid supply ineither the iiuid supplying or venting positions of the valve with respect to the passage 29 so that the hammer motor may continue to run when'drill steel rotation is interrupted.

In'Fig. 9 a modified form of the invention is disclosed, and Yin this construction a ratchet ring 35 is held against rotation by a key 36 and provided'with internal ratchet teeth 31. A pawl carrier 38 is arranged concentrically within the ratchet ring and is journaled on a bearing sleeve supported by the Vrearward portion of a rifle bar 39 similar to the rie bar above described. The pawls of the pawl carrier 38 are in reverse position from those shown in Fig. 5. A rear head block 40 has a bore 4I containing a'reciprocable piston 42 integral with a clutch member 43. This clutch member is splined at V44 to the rearward portion of the riiie bar, and has clutch teeth 45 engageable with clutch teeth 46 on the rear face of the pawl carrier. A coiled spring 41 arranged between the clutch member and a ange on the rifle barurges the clutch member toward its rearmost released position. As in the form of the invention above described, the throttle valve controls the flow of pressure uid to the bore 4I at the-rear side of the piston 42 to eiect forward movement of the clutch member into its foremost clutched position. The throttle valve also controls theV venting of the piston bore 4I at the rear side of the piston 42 to effect release of the clutch member. When the clutch member is released the rifle bar is disconnected from the pawl carrier.

The inode of operation of the improved rotation control means as illustrated in Figs. 1 to 8 is as follows: When the hammer motor is running and the parts are in the position shown in Figs. 1 and 6, the pawl carrier I4 is clutched to the stationary stub shaft I6 so that the pawl carrier is held against rotation. As the hammer piston 3 of the drill hammer motor reciprocates to eiTect percussive actuation of the drill steel the pawls I5 of the pawl carrier act against the ratchet teeth I3 of the ratchet ring I2 to hold the rifle bar 9 against rotation in one direction during the return movement of the hammer piston. The rie bar, when so held, causes a rotary motion to be imparted to the hammer piston, and this rotary piston motion is transmitted to the drill steel through the straight grooves on the piston striking bar. As the motor piston moves forwardly to effect its working stroke the pawls of the pawl carrier slip over the ratchet teeth of the ratchet ring so that the rifle bar rotates, and as a result movement of the hammer piston is unimpeded so that a powerful blow is delivered to the drill steel shank.

When it is desired to interrupt drill steel rotation for any reason, the operator may turn the throttle valve 6 to the position shown in Figs. 2 and 7, thereby to connect the bore I8 at the rear side of the piston AI9 to exhaust, so that the coiled spring 25 moves the clutch member 20 rearwardly into its rearmost released position. When the clutch member 28 is released the pawl carrier I4 and ratchetring I2 oscillate with the vriiie bar during reciprocation of the motor piston, and at that time no rotary motion is imparted to the hammer piston, and as a result drill steel rotation is interrupted while the hammer piston continues to reciprocate. When the operator again desires to effect drill steel rotation the throttle valve may be turned into the position shown in Fig. 6 to admit pressure fluid to the bore I8 at the rear side of the piston I9 to eiect forward movement of the clutch member 20 into its foremost clutched position, and as a result the pawl carrier is again held stationary and steel rotation is again eiiected by the hammer piston. Y

In the form of the invention shown in Fig. 9, when the clutch member 43 is connected the rifle bar 39 is secured to the pawl carrier 38 and the pawls of the pawl carrier engage the teeth 31 of the stationary ratchet ring 35 to hold the rifle bar against rotation in one direction during the return stroke of the hammer piston, thereby to impart a rotary motion to the hammer piston which is transmitted, in the manner -above described, to the drill steel. When the bore 4I at the rear side of the piston 42 is vented by the throttle valve the coiled spring 41 moves the clutch member rearwardly into its rearmost released position so that the riiie bar is disconnected from the pawl carrier, and as a result the riie bar can freely oscillate relative to the pawl carrier and drill steel rotation is interrupted.

In both embodiments of the invention a conventional friction clutch may be substituted for the jaw clutch disclosed without departing from the spirit of the invention, and the clutch may be mechanically actuated instead of being under the actuation of pressure iiuid. Also ifV desired, the clutch member may be moved forwardly by a coiled spring and moved rearwardly by pressure iiuid, or the clutch member may be moved in both directions by pressure fluid. In lieu of the intermittent grip mechanism disclosed a'roller grip device or other forms of grip devices might be employed.

As a result oi this invention an improved drill steel rotation mechanism for a hammer rock drill is provided whereby the drill operator may interrupt drill steel rotation at will in an improved manner. It will further be noted that by the provision of the improved clutch means associated With the pawl carrier of the ratchet and pawl mechanism the rotation of the drill steel may be controlled in an improved manner. It will further be evident that the improved structure is comparatively simple and rugged, is practically fool-proof and may be readily operated. Other uses and advantages of the invention Will be clearly apparent to those skilled in the art.

While there are in this application speciiically escribed tWo forms Which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be modied and embodied in various other forms Without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a, rock drill, rotation mechanism adapted to rotate a drill steel comprising an intermittent grip mechanism, said Vgrip mechanism including relatively rotatable, concentrically arranged ratchet and carrier elements, the latter being arranged within the former and carrying gripping means, a rifle b-ar operatively connected to said ratchet element, and clutch means operable at Will for holding said carrier element stationary or for freeing said carrier element for rotation.

2. In a rock drill, rotation mechanism adapted to rotate a drill steel comprising a rifle bar, an intermittent grip mechanism for controlling said rie bar, said grip mechanism including relatively rotatable, inner and outer elements, the inner one of which is a carrier for gripping means, and means operable at will during running of the rock drill and embodying a releasable clutch associated with said carrier for controlling the functioning thereof.

3. In a rock drill, rotation mechanism adapted to rotate a drill steel comprising an intermittent t grip mechanism, said grip mechanism including relatively rotatable elements, one of which is a carrier for gripping means, a riiie bar, and clutch means operable at will during running of the rock drill for connecting the rifle bar to or releasing said bar from said carrier.

4. In a rock drill, rotation mechanism adapted to rotate a drill steel comprising a riiie bar, intermittent grip mechanism for controlling said rie bar, said grip mechanism including relatively rotatable, inner and outer elements, the inner one of which is a carrier for gripping means. and means associated With said carrier and embodying a releasable clutch actuated by pressure iluid for controlling the functioning of said carrier. i

5. In a rock drill, rotation mechanism adapted to rotate a drill steel comprising an intermittent grip mechanism, said grip mechanism including relatively rotatable ratchet ring and carrier elements, the latter arranged Within the ratchet ring element and carrying gripping means, a riiie bar operatively connected to said ratchet ring element, and clutch means operable at Will and actuated by pressure iiuid for holding said inner carrier element stationary or for freeing said carrier element for rotation.

6. In a rock drill, rotation mechanism adapted to rotate a drill steel comprising a rifle bar, a ratchet and pawl mechanism for controlling said rifle bar, said ratchet and pawl mechanism including relatively rotatable ratchet ring and pawl carrier elements, the latter being arranged Within the former, and clutch means operable at will during running of the rock drill for controlling the rotation of said carrier element.

7. In a rock drill, rotation mechanism adapted to rotate a drill steel comprising a ratchet and pawi mechanism, said ratchet and pawl mechanism including relatively rotatable ratchet ring and pavzl carrier elements, the former surrounding the latter, a rie bar operatively connected to said ratchet ring, and clutch means operable to hold said carrier element stationary or for freeing said carrier element for rotation.

8. In a rock drill, rotation mechanism adapted to rotate a drill steel comprising a ratchet and paWl mechanism, said ratchet and pawl mechanism including relatively rotatable ratchet and paWl carrier elements, a rifle bar, and clutch means operable at will during running of the rock drill for connecting said rifle bar to said carrier element or for freeing said rifle bar for rotation relative to said carrier element.

9. In a rockv drill, rotation mechanism adapted to rotate a drill steel including a riiie bar, a ratchet and pawl mechanism for controlling said riiie bar, said ratchet and paWl mechanism comprising relatively rotatable ratchet ring and pawi carrier elements, the latter being arranged within the former, and clutch means operable at Will during running of the rock drill and associated With said pawl carrier element for controlling the functioning of said rifle bar.

10. In a rock drill, rotation mechanism adapted to rotate a drill steel including an intermittent grip device, said grip device including relatively rotatable inner and outer elements having griping means therebetween, a rifle bar, the outer rotatable one of said elements being connected to said rie bar, and means operable at will for holding said inner element stationary or for freeing the same for rotation.

Il. In a rock drill, rotation mechanism adapted to rotate a drill steel comprising a stationary pawl carrier, a rotatable ratchet ring surrounding said carrier, pawls on said carrier engaging the teeth of said ratchet ring for controlling the direction of rotation of said ratchet ring, a rifle bar connected to said ratchet ring, and releasable clutch means for holding said paWl carrier stationary and releasable at will to free said carrier for rotation.

l2. In a rock drill, rotation mechanism adapted to rotate a drill steel comprising a stationary ratchet ring, a rotatable paWl carrier arranged within said ratchet ring, pawls on said carrier engaging the teeth of said ratchet ring, a rifle bar, and clutch means operable at Will during running of the rock drill for connecting said rifle bar to said pawl carrier or for disconnecting said pawl carrier from said rifle bar.

13. In a rock drill, rotation mechanism adapted to rotate a drill steel including a rie bar, an intermittent grip device operatively connected to said riiie bar for controlling the rotation of the latter, said grip device comprising relatively rotatable, inner and outer elements including an inner carrier carrying gripping means, said rifle bar and said carrier being relatively rotatable, and means operable at will during running of the rock drill for controlling the functioning of said carrier.

14. In a rock drill, rotation mechanism adapted to rotate a drill steel including a rifle bar, an intermittent grip device operatively connected to said rifle bar for controlling rotation of the latter, said grip device including a carrier carrying gripping means, and means operable at will during running of the rock drill for connecting said rifle bar to said carrier and releasable at will to disconnect said rie bar from said carrier.

15. In a rock drill, rotation mechanism adapted to rotate a drill steel including a rifle bar, an intermittent grip device operatively connected to said rifle bar for controlling rotation of the latter, said grip device comprising relatively rotatable, inner and outer elements including an inner carrier carrying gripping means, and clutch means operable at will for holding said carrier stationary or for freeing the same for rotation.

16. In a rock drill, rotation mechanism adapted to effect rotation of a drill steel comprising an intermittent grip mechanism, said grip mechanism including an outer rotatable ring and an inner carrier for gripping means engageable with said ring, a rifle bar connected to said rotatable ring, and clutch means operable at will during running of the rock drill for holding said carrier stationary or for freeing said carrier for rotation.

17. In a rock drill, rotation mechanism adapted to effect rotation of a drill steel comprising a rifle bar, an intermittent grip mechanism for controlling said rifle bar, said grip mechanism including relatively rotatable 'elements one of which is a carrier for gripping means, said carrier having clutch teeth, and clutch means operable at will during running of the rock drill and associated with said carrier for controlling the functioning thereof, said clutch means including a shiftable jaw clutch element having clutch teeth connectible with the clutch teeth of said carrier for locking the clutch element and carrier together.

CHARLES F. OSGOOD. 

